Soluble Microfilament-Generating Multicomponent Fibers

Abstract

Microfilament-generating multicomponent fibers are provided that include a first polymer component and a second polymer component extruded together in separate contiguous polymer segments extending along the length of the fiber. The first polymer component comprises a synthetic melt-processable polymer that is substantially soluble in a first relatively benign solvent selected from water, aqueous caustic solution, and non-halogenated organic solvents. The second polymer component is formed from a second synthetic melt-processable polymer dimensioned to produce one or more microfilaments upon dissolution of the first polymer, and that is substantially soluble in an aqueous solvent selected from water and aqueous caustic solution. The two polymer components are dissolvable in different solvents.

1 . A method of forming a microfilament-generating multicomponent fiber, comprising: 
 i) providing a first molten viscous polymer composition comprising a first synthetic polymer soluble in a first solvent such that the polymer breaks apart into particles having an average particle size of no more than 1 micron after 60 minutes of exposure to the first solvent, the first solvent being selected from the group consisting of water at a temperature of 70° C. or above, water at a temperature of less than 70° C., aqueous caustic solution, and a non-halogenated organic solvent;    ii) providing a second molten viscous polymer composition comprising a second synthetic polymer soluble in a second aqueous solvent such that the polymer breaks apart into particles having an average particle size of no more than 1 micron after 60 minutes of exposure to the second aqueous solvent, the second aqueous solvent being selected from the group consisting of water at a temperature of 70° C. or above, water at a temperature of less than 70° C., and aqueous caustic solution, wherein the first solvent and the second aqueous solvent are different such that the second synthetic polymer is not dissolvable in the first solvent;    iii) extruding the first molten viscous polymer composition and the second molten viscous polymer composition together through a spinneret to form a multicomponent fiber comprising one or more separate contiguous segments of each of the first polymer composition and the second polymer composition extending the length of the fiber, wherein at least a portion of the polymer segments comprising the second polymer composition are dimensioned to form microfilaments having a denier of less than 1.5; and    iv) collecting the multicomponent fiber.    
   
   
       2 . The method of  claim 1 , further comprising dissolving the first polymer composition, thereby forming one or more microfilaments comprising the second polymer composition.  
   
   
       3 . The method of  claim 1 , further comprising forming a fabric comprising a plurality of the collected multicomponent fibers.  
   
   
       4 . The method of  claim 3 , further comprising dissolving the first polymer composition, thereby forming a fabric comprising a plurality of microfilaments comprising the second polymer composition.  
   
   
       5 . The method of  claim 1 , wherein the first solvent is water at a temperature of less than 70° C. and the second aqueous solvent is water at a temperature of 70° C. or above.  
   
   
       6 . The method of  claim 1 , wherein the first solvent is water at a temperature of less than 70° C. and the second aqueous solvent is aqueous caustic solution.  
   
   
       7 . The method of  claim 1 , wherein the first solvent is water at a temperature of 70° C. or above and the second aqueous solvent is aqueous caustic solution.  
   
   
       8 . The method of  claim 1 , wherein the first solvent is a non-halogenated organic solvent and the second aqueous solvent is water at a temperature of less than 70° C.  
   
   
       9 . The method of  claim 1 , wherein the first solvent is a non-halogenated organic solvent and the second aqueous solvent is water at a temperature of 70° C. or above.  
   
   
       10 . The method of  claim 1 , wherein the first solvent is a non-halogenated organic solvent and the second aqueous solvent is aqueous caustic solution.  
   
   
       11 . The method of  claim 1 , wherein the first solvent is aqueous caustic solution and the second aqueous solvent is water at a temperature of 70° C. or above.  
   
   
       12 . The method of  claim 1 , wherein said first polymer is selected from the group consisting of sulfonated polyesters, sulfonated polystyrene, ethylene vinyl alcohol, polyvinyl alcohol, polyethylene oxide, polyglycolic acid, polylactic acid, polycaprolactone, and polystyrene.  
   
   
       13 . The method of  claim 1 , wherein said second polymer is selected from the group consisting of sulfonated polyesters, sulfonated polystyrene, ethylene vinyl alcohol, polyvinyl alcohol, polyethylene oxide, polyglycolic acid, polylactic acid, and polycaprolactone.  
   
   
       14 . The method of  claim 1 , wherein said first polymer is polyvinyl alcohol or a sulfonated polyester and said second polymer is polylactic acid.  
   
   
       15 . The method of  claim 1 , wherein said first polymer is polystyrene and said second polymer is selected from the group consisting of sulfonated polyesters, sulfonated polystyrene, ethylene vinyl alcohol, polyvinyl alcohol, polyethylene oxide, polyglycolic acid, polylactic acid, and polycaprolactone.  
   
   
       16 . The method of  claim 1 , wherein said one or more microfilaments have a fineness of less than about 1.0 denier.  
   
   
       17 . The method of  claim 16 , wherein said one or more microfilaments have a fineness of less than about 0.5 denier.  
   
   
       18 . The method of  claim 1 , wherein the fiber has a cross-sectional configuration selected from the group consisting of pie/wedge, segmented round, segmented oval, segmented ribbon, segmented multi-lobal, segmented cross, and islands-in-the-sea.  
   
   
       19 . The method of  claim 1 , wherein the fiber has a pie/wedge cross-sectional configuration.  
   
   
       20 . The method of  claim 1 , wherein the fiber has an islands-in-the-sea cross-sectional configuration.  
   
   
       21 . A fiber bundle comprising a plurality of microfilaments generated from one or more multicomponent fibers made according to the process of  claim 2 .  
   
   
       22 . The fiber bundle of  claim 21 , wherein the microfilaments have a cross-sectional shape selected from the group consisting of pie wedge, multi-lobal, hexagonal, rectangular, oval, and circular.  
   
   
       23 . A fabric comprising the fiber bundle of  claim 21 .  
   
   
       24 . The fabric of  claim 23 , wherein the fabric is selected from the group consisting of woven fabrics, nonwoven fabrics, and knit fabrics.  
   
   
       25 . A fabric comprising a plurality of multicomponent fibers made according to the process of  claim 1 .  
   
   
       26 . The fabric of  claim 25 , wherein the fabric is selected from the group consisting of woven fabrics, nonwoven fabrics, and knit fabrics.  
   
   
       27 . A method of forming a microfilament-generating multicomponent fiber, comprising: 
 i) providing a first molten viscous polymer composition comprising a first synthetic polymer soluble in water such that the polymer breaks apart into particles having an average particle size of no more than 1 micron after 60 minutes of exposure to water;    ii) providing a second molten viscous polymer composition comprising a second synthetic polymer soluble in an aqueous caustic solution such that the polymer breaks apart into particles having an average particle size of no more than 1 micron after 60 minutes of exposure to the aqueous caustic solution, wherein the second synthetic polymer is not dissolvable in water;    iii) extruding the first molten viscous polymer composition and the second molten viscous polymer composition together through a spinneret to form a multicomponent fiber comprising one or more separate contiguous segments of each of the first polymer composition and the second polymer composition extending the length of the fiber, wherein at least a portion of the polymer segments comprising the second polymer composition are dimensioned to form microfilaments having a denier of less than 1.5; and    iv) collecting the multicomponent fiber.    
   
   
       28 . The method of  claim 27 , further comprising dissolving the first polymer composition, thereby forming one or more microfilaments comprising the second polymer composition.  
   
   
       29 . The method of  claim 27 , further comprising forming a fabric comprising a plurality of the collected multicomponent fibers.  
   
   
       30 . The method of  claim 29 , further comprising dissolving the first polymer composition, thereby forming a fabric comprising a plurality of microfilaments comprising the second polymer composition.  
   
   
       31 . The method of  claim 27 , wherein said first polymer is polyvinyl alcohol or a sulfonated polyester and said second polymer is polylactic acid.